Low-carbon high-efficiency sewage treatment device based on phycomycete granular sludge and operation method of low-carbon high-efficiency sewage treatment device

Abstract

The invention discloses a low-carbon high-efficiency sewage treatment device based on phycomycete granular sludge, which is composed of a primary reaction zone, a light supplementing zone and a secondary reaction zone which are communicated with one another, and the primary reaction zone, the light supplementing zone and the secondary reaction zone are all mounted on a base; the primary reaction area is integrally of a cylinder structure, is a core sewage treatment area, and comprises a water inlet, an inner cylinder, an inner cylinder baffle, an aeration device, a stirring device, a perforated plate, a backflow area and an overflow weir; the whole reactor device disclosed by the invention is in a long cylinder shape, and the space utilization efficiency is improved by adopting effective space partition distribution, so that the occupied area of the reactor is effectively reduced; the continuous flow phycomycete granule sludge treatment device which is efficient in treatment, stable in operation, low in energy consumption and high in adaptability is successfully constructed through coupling treatment of a primary reaction area and a secondary reaction area and cooperative assistance of a light supplementing area and an integrated magnetic field-temperature control partition base.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge and its operation method. Background Technology

[0002] In recent years, my country has been actively exploring and promoting pollution reduction and carbon reduction in the field of wastewater treatment. However, the traditional activated sludge process (CAS), as the most commonly used biological treatment process in wastewater treatment systems, struggles to meet the sustainable development needs under the "dual carbon" goal due to its high energy consumption, greenhouse gas emissions, and challenges in disposing of excess sludge. In contrast, the microalgal-bacterial granular sludge (MBGS) process can achieve the recycling of oxygen (O2) and carbon dioxide (CO2) through the synergistic coupling of photosynthesis and respiration, significantly reducing aeration energy consumption and carbon emissions. Furthermore, it integrates the resource potential of microalgae with the efficient settling properties of granular sludge, and is expected to become a mainstream, green, and sustainable wastewater treatment process in the future.

[0003] However, current MBGS technology mainly faces three major bottlenecks:

[0004] 1) Unstable continuous flow operation: Existing MBGS systems mostly operate in sequencing batch reactors, which suffer from problems such as discontinuous effluent, low volumetric utilization, and difficulty in large-scale application. In continuous flow mode, particle breakup and algae-bacteria separation are prone to occur, leading to a decrease in nitrogen and phosphorus removal efficiency.

[0005] 2) High energy consumption: Traditional aeration combined with mechanical stirring accounts for more than 60% of the electricity consumption per ton of water, and the oxygen supply advantage of algae photosynthesis is not fully utilized.

[0006] 3) Low light efficiency: Insufficient light intensity in deep water areas leads to the inactivation of bottom algae, limiting the system's treatment efficiency. Furthermore, MBGS requires precise temperature and nutrient control, controllable gas supply, and efficient space utilization to ensure a highly efficient and stable reaction process. Some existing solutions employ top or side illumination from the light source. For example, patent CN105692884A discloses a sequencing batch reactor (SBAR) with a double-layered cylindrical structure serving airlift circulation and granular sludge cultivation. The light source is located at the top, and the operation is a periodic intermittent process of "influent-anaerobic-aeration-sedimentation-drainage." Patent CN105961303A discloses a fish-bacteria-algae symbiotic ecological aquaculture system. Its photobioreactor has a single-layer structure with an internal strip light source wound around the membrane module, aiming to ensure uniform illumination of the suspended microalgae. Neither of the two patented solutions mentioned above involves a continuous flow operation mode, nor does it involve a design that uses multi-layer sleeves to achieve zoned processing and three-dimensional supplementary lighting. Furthermore, the top-mounted and side-mounted light sources result in a large space requirement.

[0007] 4) Existing patent solutions, such as CN120483392, use magnetic iron oxide nanoparticles and permanent magnets to establish a static magnetic field for algae aggregation and nucleation, and improve microbial activity. However, this is only a simple and direct biological stimulus. The water stirring in the sewage treatment process requires a separate drive mechanism, which further increases the size of the device.

[0008] Other existing patent technologies, such as CN121470696A, disclose a wastewater treatment device based on algae and bacteria granular sludge in three zones, but the specific wastewater treatment process has not been substantially improved or specifically disclosed; it is merely a conventional existing operation.

[0009] Therefore, to address the above issues, a low-carbon and high-efficiency wastewater treatment device based on algae and bacteria granular sludge and its operation method are proposed. Summary of the Invention

[0010] In order to overcome the above-mentioned defects of the prior art, the present invention provides a low-carbon and high-efficiency sewage treatment device based on algae and bacteria granular sludge and its operation method.

[0011] The technical solution of this invention is as follows:

[0012] In a first aspect, the present invention provides a low-carbon and high-efficiency wastewater treatment device based on algae and bacteria granular sludge. The main body of the device consists of an interconnected primary reaction zone, a supplementary lighting zone, and a secondary reaction zone, all of which are mounted on an integrated base.

[0013] The primary reaction zone is a cylindrical structure and serves as the core wastewater treatment area for achieving efficient pollutant removal and a "saturation-starvation" effect. It includes an inlet, inner cylinder, inner cylinder baffles, aeration device, stirring device, perforated plate, reflux zone, and overflow weir.

[0014] The inlet is located below the primary reaction zone; the inner cylinder is located at the center of the primary reaction zone, serving as the main reaction area (i.e., the aerobic zone); the aeration device is located directly below the inner cylinder; the stirring device is located at the center of the inner cylinder and fixed to the bottom of the primary reaction zone; the perforated plate is located directly above the inner cylinder, with a gap between it and the top of the inner cylinder, forming a gas buffer diffusion zone; the reflux zone is separated from the inner cylinder by the inner cylinder baffle; the overflow weir is located above the primary reaction zone, temporarily storing the wastewater flowing out through the perforated plate.

[0015] The supplemental lighting area provides efficient and suitable illumination for the reaction system. It includes a focusing device and a supplemental lighting device.

[0016] The focusing device is located next to the reactor to collect and concentrate sunlight, which is then coupled to the supplementary lighting device via a beam beamer. The supplementary lighting device is situated between the primary and secondary reaction zones, and is an annular cylindrical structure. Its annular diameter is determined based on the specific diameters of the primary and secondary reaction zones and the illumination intensity of the layered light source.

[0017] The secondary reaction zone is an annular cylinder located around the supplemental lighting device, which can further treat wastewater and achieve sedimentation and separation of aged sludge. This zone includes a guide pipe, a self-driven stirring device, a sludge hopper, and a water outlet.

[0018] Wastewater flows into the secondary reaction zone through the overflow weir outlet via a guide pipe, where it undergoes further treatment using the MBGS process. The self-driven stirring device is directly driven by the hydraulic pressure of the swirling water inlet of the secondary reaction zone, eliminating the need for an additional motor. The sludge hopper is located at the bottom of the secondary reaction zone, and the outlet is located on the lower outer side of the secondary reaction zone.

[0019] The base is a sealed, flat, rectangular cavity structure, installed at the bottom directly below the main body of the reactor device.

[0020] Preferably, the water inlet of the primary reaction zone is supplied by two parallel pipes.

[0021] Preferably, the layout of the inner cylinder baffle in the primary reaction zone can be divided into three parts from bottom to top: an expansion section, a straight cylinder section, and a contraction section.

[0022] Preferably, the width of the aeration system in the primary reaction zone is consistent with the width of the straight section of the inner cylinder. The inner cylinder and the reflux zone serve as the aerobic and anoxic zones in the MBGS process, respectively, improving the system's treatment efficiency. Preferably, the aeration system can be connected to treated CO2-containing waste gas; the aeration gas is a mixture of air and CO2, with CO2 accounting for 10% to 30%; more preferably, the CO2 proportion is 15%. Preferably, the aeration system can also be connected to a micro / nano bubble device to achieve micron-level aeration bubbles.

[0023] Preferably, the stirring device in the primary reaction zone is driven directly by the magnetic field of the base to rotate the fan blades, eliminating the need for an additional motor. The height of the inner cylinder's straight section is H, and the stirring device is equipped with two transparent fan blades, positioned at 1 / 4H and 3 / 4H below the top of the inner cylinder's straight section, respectively, to ensure thorough stirring. Preferably, transparent fan blades are used to minimize the light-blocking effect of the fan blades.

[0024] Preferably, the perforated plate in the primary reaction zone is made of transparent, corrosion-resistant and high-strength material, and is a concave arched plate with a round hole diameter of 3~5 mm, an opening rate of 50%~60%, an alternating arrangement of equilateral triangles, and a slight curvature.

[0025] Preferably, the supplemental lighting device uses the middle height of the reactor as the dividing point and adopts a layered multi-band light source structure, which can significantly improve algal biomass and the system's nitrogen and phosphorus removal efficiency.

[0026] Preferably, the outer walls of both the primary reaction zone and the supplementary lighting device are made of transparent material, and the supplementary lighting device can provide supplementary lighting for both the primary and secondary reaction zones simultaneously.

[0027] Preferably, the secondary reaction zone is equipped with a guide pipe with a precisely designed incident angle and flow velocity, which enables the wastewater to form a stable vortex within the secondary reaction zone. This not only enhances mixing and mass transfer but also provides a power source for subsequent hydraulically driven stirring, achieving preliminary energy recovery.

[0028] Preferably, four sets of self-driven stirring devices are provided in the secondary reaction zone, arranged in a vertical cross shape and placed at the center of the inner diameter of the ring; a conical spiral stirring device with a transparent circular arc thread is selected.

[0029] Preferably, the outlet of the secondary reaction zone is set in a parallel direction to the direction of the guide pipe, so as to ensure that the sewage can complete a complete swirling process in the secondary reaction zone, thereby extending the hydraulic retention time.

[0030] Preferably, the base is an integrated magnetic field-temperature control partitioned base, which integrates a magnetic generation module and a temperature control module.

[0031] Preferably, the magnetic generation module of the base is divided into zones according to the reaction characteristics of the primary and secondary reaction zones, and adopts different operating modes according to the reaction stage. The temperature control module of the base operates the temperature control system independently according to the set temperature.

[0032] Secondly, the present invention provides an operation method for a low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge as described in the first aspect, comprising the following steps:

[0033] S1. Sludge Inoculation and System Start-up Phase

[0034] Sludge inoculation and activation: Mature algae and bacteria granular sludge with different initial sludge concentrations are added to the inner cylinder of the primary reaction zone and the secondary reaction zone, respectively.

[0035] Base system activation: Turn on the base's temperature control module, set and maintain the system temperature; turn on the magnetic generation module and set the zones, start the "constant magnetic field" mode for the primary reaction zone, and temporarily disable the magnetic field in the secondary reaction zone or use a low-intensity background magnetic field.

[0036] System acclimatization: The system adopts a gradual load start-up method, synchronously turns on the supplementary lighting device, and operates according to a layered supplementary lighting strategy.

[0037] S2, Sunlight Period Operation Mode

[0038] During the illumination period: In addition to absorbing sunlight at the top of the reactor, the concentrator collects sunlight and provides stratified supplementary lighting to the reactor through the supplementary lighting device.

[0039] The core treatment in the primary reaction zone: wastewater is mixed with high-concentration MBGS in the inner cylinder, and organic matter and nutrients are rapidly absorbed and degraded ("fed"). The treated mixed liquor rises through the perforated plate, where large-diameter MBGS particles are intercepted. The intercepted granular sludge slides down to the return zone under gravity and rebound. The anoxic environment in this zone prompts microorganisms to use endogenous carbon sources for denitrification ("starvation"). Subsequently, the intercepted granular sludge is returned to the bottom of the inner cylinder, completing the "fed-starvation" cycle.

[0040] Because the supplemental lighting device provides illumination, algae photosynthesize and produce oxygen, increasing the dissolved oxygen (DO) concentration in the inner cylinder. The aeration device is completely shut off or operates at only very low intensity, significantly reducing energy consumption. The magnetic field at the base drives the transparent fan blades of the mixing device to rotate slowly, ensuring thorough mixing and contact between the MBGS and the wastewater while minimizing shading.

[0041] Secondary Reaction Zone Deep Treatment and Settling: The supernatant from the primary treatment is temporarily stored in the overflow weir and flows tangentially into the secondary reaction zone through the guide pipe, forming a vortex. The vortex hydraulically drives a self-propelled stirring device to rotate, eliminating the need for a motor and achieving energy-saving mixing. In this zone, pollutants are further degraded. The centrifugal force generated by the vortex and the magnetic field generated by the base magnetic generator module help screen sludge particles, with aged, fine particles gathering towards the center. The sludge hopper begins to collect the settled aged sludge. The treated clean water flows out through the outlet.

[0042] S3, Dark Period Operation Mode

[0043] The reaction zone mode is switched as follows: Lighting ceases, and algae stop producing oxygen. The aeration device automatically activates based on dissolved oxygen (DO) levels, employing a "pulse aeration" mode. Aeration only occurs when DO is too low, ensuring sufficient oxygen for nitrifying bacteria while maximizing energy efficiency. The magnetic field in the primary reaction zone switches to an "intermittent magnetic field" mode; furthermore, the magnetic field intermittently drives continuous stirring to ensure smooth reaction. Periodic magnetic stimulation helps maintain the activity of the microbial community, preventing aging and inertia.

[0044] Enhanced sedimentation in the secondary reaction zone: The magnetic field strength in the secondary reaction zone can be appropriately increased to promote the flocculation and sedimentation of MBGS by utilizing the magnetic flocculation effect.

[0045] S4. Routine Maintenance and Sludge Management

[0046] Water effluent monitoring: Regularly test the water quality at the effluent outlet and fine-tune parameters such as influent flow rate, aeration intensity, and magnetic field mode based on the effluent water quality.

[0047] Sludge Discharge and Recycling: Periodically open the sludge discharge valve at the bottom of the sludge hopper to discharge the accumulated aged sludge. The discharged sludge can be further processed for digestion, or the still active granular sludge can be recycled, cultivated, and then added back to the reactor to maintain the activity and concentration of sludge in the system.

[0048] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0049] 1) This application employs a uniquely designed magnetization and acclimatization mode, as well as a light-period operation mode / nighttime (dark-period) operation mode, and different magnetization modes for the primary and secondary zones. This allows the magnetic field to intermittently drive the stirring continuously, ensuring the smooth progress of the reaction. Periodic magnetic stimulation helps maintain the activity of the microbial community and prevents it from aging and becoming inert.

[0050] 2) This application adopts a three-layer concentric stacked cylindrical structure. By designing the tops of the first and second cylindrical bodies to be lower than the top of the third cylindrical body, a continuous flow operation mode is achieved, where wastewater from the primary reaction zone continuously overflows into the secondary reaction zone. Simultaneously, an annular supplementary lighting zone is positioned between the inner and outer cylindrical bodies, enabling simultaneous supplementary lighting to both the inner primary reaction zone and the outer secondary reaction zone. This, combined with the return flow zone formed by the guide tube, ensures that the granular sludge receives ample illumination while adhering closely to the supplementary lighting zone during circulation. This overall technical concept is based on "continuous flow + three-dimensional supplementary lighting + zoned treatment."

[0051] 3) The integrated magnetic field-temperature control partition base of the present invention integrates a magnetic generation partition module and a temperature control module. Through the synergistic effect of magnetic field and ambient temperature control, it significantly accelerates the degradation rate of pollutants and significantly improves the system's adaptability to regional and seasonal changes, achieving high efficiency and energy saving. The base and the spectrum-adaptive layered supplementary lighting device form a "magnetic-thermal-light" multi-field synergistic effect, which significantly improves the pollutant degradation efficiency and nitrogen and phosphorus removal capabilities. In addition, the first magnetic generation module in the magnetic stimulation stirring mechanism is arranged below the primary reaction zone. By generating a changing magnetic field, it simultaneously achieves two functions: (1) driving the magnetic stirring blades to rotate, achieving non-contact stirring; (2) stimulating microorganisms through the changing magnetic field, promoting their growth and metabolism. This dual function of "non-contact stirring + biostimulation" not only drives mechanical stirring but also plays a biostimulatory role, realizing the organic unity of mass transfer and efficiency enhancement. Combining the magnetic stimulation stirring mechanism with the three-layer sleeve structure and filter plate structure forms a synergistic effect of "mass transfer efficiency enhancement + biostimulation + three-dimensional supplementary lighting + particle interception", and can also greatly reduce the volume occupied by the device.

[0052] 4) The aeration device in the primary reaction zone of this invention provides a controllable gas supply and can be connected to treated CO2-containing waste gas, which can not only supplement the carbon source required for MBGS reaction, but also use MBGS to fix CO2 to reduce carbon emissions from waste gas; the micro-nano device makes the aeration bubbles reach the micron level, which helps the bubbles to mix better with MBGS, accelerate the reaction rate, and maintain the stability of MBGS particles.

[0053] 5) The present invention separates the inner cylinder of the primary reaction zone and the reflux zone. The synergistic effect of the two is the key to realizing the "satisfaction-starvation" effect in the MBGS process.

[0054] 6) The perforated plate is cleverly positioned in the primary reaction zone of this invention, which not only ensures the smooth passage of sewage but also effectively prevents mature algae and bacteria granular sludge from flowing out with the sewage, thereby ensuring the stable operation of the MBGS system. Its arc-shaped structure not only makes it easy for granular sludge to slide off the surface, thereby reducing plate accumulation, but also increases its structural strength to withstand sludge pressure.

[0055] 7) The secondary reaction zone of the present invention is tangentially fed with water through a guide pipe, forming a circulation in the annular cylinder and driving the stirring device to rotate, which is highly efficient and energy-saving, and is especially suitable for long-term continuous operation; and the transparent arc-shaped spiral stirring device can significantly improve the CO2 fixation and mass transfer efficiency of the system, which helps MBGS maintain particle size stability in practical applications.

[0056] 8) The static magnetic field was transformed into a variable magnetic field, and it was even more unexpected to use the variable magnetic field to simultaneously drive the stirring blades to rotate. The magnetic stimulation stirring mechanism was combined with the three-layer sleeve structure and filter plate structure to form a synergistic effect of "mass transfer enhancement + biostimulation + three-dimensional supplementary lighting + particle retention".

[0057] Overall, the reactor device involved in this invention adopts a long cylindrical shape. By employing effective spatial partitioning to improve space utilization efficiency, the reactor's footprint is effectively reduced. The use of a changing magnetic field for bio-stimulation and mechanical stirring further reduces volume. The filter plate is a downward-protruding curved panel with filter holes smaller than the particle size of the algae and bacteria granular sludge (typically in the millimeter range). Its function is an integrated "guide-interception-recirculation": when wastewater flows upward in the stirring reaction zone, the curved panel smoothly guides the water flow, directing most of the granular sludge to the surrounding recirculation zone, achieving particle recycling. Only treated wastewater is allowed to overflow through the filter holes into the secondary reaction zone. This shape design and functional integration further reduce volume. Furthermore, through the coupling treatment of the primary and secondary reaction zones, and relying on the synergistic assistance of the supplementary lighting zone and the integrated magnetic field-temperature control partition base, a continuous flow algae and bacteria granular sludge treatment device with high efficiency, stable operation, low energy consumption, and strong adaptability has been successfully constructed. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of a low-carbon and high-efficiency wastewater treatment device based on algae and bacteria granular sludge according to the present invention.

[0059] Figure 2 This is a top view of a low-carbon, high-efficiency wastewater treatment device based on algae and bacteria granular sludge according to the present invention.

[0060] Figure 3 This is a schematic diagram of the structure of the inner cylinder baffle in the primary reaction zone of the present invention;

[0061] Explanation of reference numerals in the attached drawings: 100: Primary reaction zone; 101: Inlet; 102: Inner cylinder; 103: Inner cylinder baffle; 104: Aeration device; 105: Stirring device; 106: Perforated plate; 107: Return zone; 108: Overflow weir; 200: Supplemental lighting zone; 201: Light collecting device; 202: Supplemental lighting device; 300: Secondary reaction zone; 301: Guide pipe; 302: Self-driven stirring device; 303: Sludge hopper; 304: Outlet; 400: Base. Detailed Implementation

[0062] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0063] Example 1

[0064] like Figure 1 , 2 As shown, this embodiment provides a low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge. The main body of the device consists of an interconnected primary reaction zone (100), a supplementary lighting zone (200), and a secondary reaction zone (300), all mounted on an integrated base (400). The structure and connection methods of the device will be described in detail below.

[0065] The primary reaction zone (100) of the device provided by the present invention is a cylindrical structure, which is the core wastewater treatment area for achieving efficient removal of pollutants and the "satisfaction-starvation" effect. It includes an inlet (101), an inner cylinder (102), an inner cylinder baffle (103), an aeration device (104), a stirring device (105), a perforated plate (106), a return zone (107), and an overflow weir (108).

[0066] The inlet (101) is located below the primary reaction zone (100), and water is introduced from below using two parallel pipes. The inner cylinder (102) is located at the center of the primary reaction zone (100), serving as the main reaction area (i.e., the aerobic zone) of the primary reaction zone (100). The layout of the inner cylinder baffle (103) can be divided into three parts from bottom to top: an expansion section, a straight section, and a contraction section. Figure 3The aeration device (104) is located directly below the inner cylinder (102), and its width is consistent with the width of the straight section of the inner cylinder (102). The aeration system can be connected to treated waste gas containing CO2, and the aeration gas is a mixture of air and CO2, with CO2 accounting for 15%. The aeration system can also be connected to a micro-nano bubble device to make its aeration bubbles reach the micron level. The stirring device (105) is located in the center of the inner cylinder (102) and fixed at the bottom of the primary reaction zone. The transparent fan blades are directly driven to rotate by the magnetic field of the base, without the need for an additional motor. The height of the straight section of the inner cylinder is H. The stirring device has two transparent fan blades, located at 1 / 4H and 3 / 4H below the top of the straight section of the inner cylinder, respectively, to ensure sufficient stirring. The perforated plate (106) is located directly above the inner cylinder (102) and has a gap with the top of the inner cylinder to form a gas buffer diffusion zone. It is made of transparent, corrosion-resistant and high-strength material, and is a concave arched plate with a round hole diameter of 3~5 mm, an opening rate of 50%~60%, and an alternating equilateral triangle arrangement with a slight curvature. The reflux zone (107) is separated from the inner cylinder (102) by the inner cylinder baffle (103). The reflux zone can provide a short-term hypoxic environment for MBGS, which is conducive to the efficient removal of pollutants such as ammonia nitrogen. The synergistic effect of the inner cylinder (102) and the reflux zone (107) is the key to realizing the "satisfaction-starvation" effect in the MBGS process. The overflow weir (108) is set directly above the primary reaction zone (100) to temporarily store the sewage flowing out through the perforated plate (106).

[0067] The supplemental lighting zone (200) provides efficient and suitable illumination for the reaction system. It includes a concentrator (201) and a supplemental lighting device (202). The concentrator (201) is located next to the reactor to collect and concentrate sunlight, and then couples the concentrated light to the supplemental lighting device (202) through a beam beam. The supplemental lighting device (202) is located between the primary reaction zone and the secondary reaction zone, and is in the form of an annular cylinder. The annular diameter of the supplemental lighting zone can be determined according to the specific diameters of the primary and secondary reaction zones and the illumination intensity of the layered light source. The supplemental lighting device uses the middle height of the reactor as the dividing point and adopts a layered multi-band light source structure, which can significantly improve algal biomass and the system's nitrogen and phosphorus removal efficiency. The outer walls of both the primary reaction zone and the supplemental lighting device are made of transparent material, and the supplemental lighting device (202) can simultaneously provide illumination for the primary reaction zone (100) and the secondary reaction zone (300).

[0068] The secondary reaction zone (300) is an annular cylinder located around the supplementary lighting device. This zone includes a guide pipe (301), a self-driven stirring device (302), a sludge hopper (303), and an outlet (304). This zone can further treat wastewater and achieve sedimentation and separation of aged sludge. The guide pipe (301) is located at the overflow weir outlet. A guide pipe with a precisely designed incident angle and flow velocity is installed to create a stable vortex in the secondary reaction zone, which not only enhances mixing and mass transfer but also provides a power source for subsequent hydraulically driven stirring, achieving preliminary energy recovery. The self-driven stirring device (302) is a conical spiral stirring device with a transparent circular arc thread. The fan blades are directly driven by the hydraulic force of the vortex inlet water in the secondary reaction zone, without the need for an additional motor. The four sets of devices are vertically arranged and located at the center of the inner diameter of the ring. The sludge hopper (303) is located at the bottom of the secondary reaction zone (300). The outlet (304) is located in the lower outer area of ​​the secondary reaction zone (300), and the outlet is parallel to the direction of the guide pipe.

[0069] The base (400) is a sealed, flat, rectangular cavity structure, installed directly below the bottom of the reactor body. It uses an integrated magnetic field-temperature control partitioned base, which integrates a magnetic generation module and a temperature control module. The magnetic generation module partitions the primary and secondary reaction zones according to their reaction characteristics and adopts different operating modes according to the reaction stage. The temperature control module independently operates the temperature control system according to the set temperature.

[0070] The specific method for wastewater treatment using the low-carbon, high-efficiency wastewater treatment device based on algae and bacteria granular sludge provided in this embodiment is as follows:

[0071] S1. Sludge Inoculation and System Start-up Phase

[0072] Sludge inoculation and activation: Mature bacterial granular sludge (MBGS) is added to the inner cylinder (102) of the primary reaction zone (100) to make the initial sludge concentration reach 6 g / L; mature MBGS is added to the secondary reaction zone (300) to control the initial sludge concentration at 3 g / L.

[0073] Base system activation: Turn on the temperature control module of the base (400) and set and maintain the system temperature at 25±2℃. Turn on the magnetic generation module and set the zones. Start the "constant magnetic field" mode for the primary reaction zone and set the intensity to 5 mT. The magnetic field of the secondary reaction zone is not turned on or a low intensity background magnetic field is used.

[0074] System acclimatization: A gradual load start-up method is adopted, specifically as follows: Days 1-3: Control the influent load to 50% of the design value; Days 4-7: Gradually increase to 80% of the design value; After Day 8: Reach the design full load operation. Simultaneously turn on the supplemental lighting device (202) and operate according to the spectral ratio of surface blue light (450-470 nm) and middle and lower layer red light (630-660 nm).

[0075] S2, Daytime (Sunlight Period) Operation Mode

[0076] During the illumination period: In addition to absorbing sunlight at the top of the reactor, the concentrator (201) collects sunlight and provides stratified supplementary lighting to the reactor through the supplementary lighting device (202). The surface layer of the reactor receives blue light (450-470nm), which promotes algal photosynthesis and inhibits filamentous bacteria; the middle and lower layers receive red light (630-660nm), which enhances the transmission capacity and ensures the light needs of the bottom algae.

[0077] The core treatment in the primary reaction zone: wastewater is mixed with high-concentration MBGS in the inner cylinder (102), where organic matter and nutrients are rapidly absorbed and degraded ("saturated"). The treated mixed liquor rises through the perforated plate (106), where large-diameter MBGS (particle size > 3 mm) are intercepted. The intercepted particles slide down to the return zone (107) under gravity and rebound. The anoxic environment in this zone prompts microorganisms to use endogenous carbon sources for denitrification ("starvation"). Subsequently, the granular sludge is returned to the bottom of the inner cylinder (102), completing the "saturated-starvation" cycle.

[0078] As the supplemental lighting device (202) provides illumination, algae photosynthesize and produce oxygen, increasing the dissolved oxygen (DO) concentration in the inner cylinder (102). The aeration device (104) is completely shut off or operates at only very low intensity, significantly reducing energy consumption. The transparent fan blades of the base magnetic-driven stirring device (105) rotate slowly, ensuring thorough mixing and contact between sludge, wastewater, and algae while minimizing shading.

[0079] Secondary Reaction Zone Deep Treatment and Sedimentation: The supernatant from the primary treatment flows tangentially into the secondary reaction zone (300) through the guide pipe (301), forming a vortex. The vortex hydraulically drives the transparent arc-shaped spiral of the self-driven stirring device (302), achieving energy-saving mixing without the need for a motor. In this zone, pollutants are further degraded. The centrifugal force generated by the vortex and the magnetic field force generated by the base magnetic generation module help to screen sludge particles, with aged fine particles gathering towards the center. The sludge hopper (303) begins to collect the settled aged sludge. The treated clean water flows out through the outlet (304).

[0080] S3, Night (Dark Period) Operating Mode

[0081] The reaction zone mode is switched as follows: when light is stopped, algae stop producing oxygen. Based on the dissolved oxygen (DO) probe feedback, the aeration device (104) is automatically activated, using a "pulse aeration" mode (aeration for 10 minutes, stop for 20 minutes), aerating only when DO is too low, ensuring the oxygen required by nitrifying bacteria while maximizing energy conservation. The magnetic field in the primary reaction zone (100) is switched to an "intermittent magnetic field" mode (on for 2 hours, off for 1 hour); in addition, the magnetic field intermittently drives the stirring to run continuously, ensuring the smooth progress of the reaction. Periodic magnetic stimulation helps maintain the activity of the microbial community and prevents it from aging and becoming inert.

[0082] Enhanced sedimentation in the secondary reaction zone: The magnetic field strength of the secondary reaction zone (300) can be appropriately increased (5-10 mT) to promote the flocculation and sedimentation of aged MBGS (particle size ≤1.5mm) by utilizing the magnetic flocculation effect.

[0083] S4. Routine Maintenance and Sludge Management

[0084] Water effluent monitoring: Regularly test the water quality at the outlet (304) and fine-tune parameters such as influent flow rate, aeration intensity, and magnetic field mode according to the water quality.

[0085] Sludge discharge and recycling: Periodically open the sludge discharge valve at the bottom of the sludge hopper (303) to discharge the enriched aged sludge. The discharged sludge can be used for subsequent digestion treatment, or the still active granular sludge can be recycled, cultivated, and then added back to the reactor to maintain the activity and concentration of sludge in the system.

[0086] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.

Claims

1. A low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge, characterized in that, It consists of an interconnected primary reaction zone, a supplementary lighting zone, and a secondary reaction zone, all of which are mounted on a base. The primary reaction zone is a cylindrical structure and is the core wastewater treatment area, including an inlet, an inner cylinder, an inner cylinder baffle, an aeration device, a stirring device, a perforated plate, a return zone, and an overflow weir. The inlet is located below the primary reaction zone; the inner cylinder is located at the center of the primary reaction zone, serving as the main reaction area (i.e., the aerobic zone); the aeration device is located directly below the inner cylinder; the stirring device is located at the center of the inner cylinder and fixed to the bottom of the primary reaction zone; the perforated plate is located directly above the inner cylinder, with a gap between it and the top of the inner cylinder, forming a gas buffer diffusion zone; the reflux zone is separated from the inner cylinder by the inner cylinder baffle; the overflow weir is located above the primary reaction zone, temporarily storing the wastewater flowing out through the perforated plate. The supplemental lighting area provides efficient and suitable illumination for the reaction system; it includes a focusing device and a supplemental lighting device. The light-concentrating device is located next to the reactor to collect and concentrate sunlight, and then the concentrated light is coupled to the supplementary light device through a beam beam. The supplementary light device is located in the middle of the primary reaction zone and the secondary reaction zone, and is in the form of an annular cylinder. Its annular diameter is determined according to the specific diameters of the primary reaction zone and the secondary reaction zone and the light intensity of the layered light source. The secondary reaction zone is an annular cylinder located around the supplementary lighting device, which can further treat wastewater and achieve sedimentation and separation of aged sludge; this zone includes a guide pipe, a self-driven stirring device, a sludge hopper, and a water outlet; Wastewater flows into the secondary reaction zone through the guide pipe at the overflow weir outlet and is further treated using the MBGS process; the self-driven stirring device is directly driven by the swirling water inlet of the secondary reaction zone to rotate the fan blades, eliminating the need for an additional motor; the sludge hopper is located at the bottom of the secondary reaction zone; and the outlet is located on the lower outer side of the secondary reaction zone. The base is a sealed, flat, rectangular cavity structure, installed at the bottom directly below the main body of the reactor device.

2. The low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to claim 1, characterized in that: The water inlet of the primary reaction zone is supplied by two parallel pipes. The layout of the inner cylinder baffle in the primary reaction zone can be divided into three parts from bottom to top: the expansion section, the straight cylinder section, and the contraction section. The width of the aeration system in the primary reaction zone is consistent with the width of the straight section of the inner cylinder. The inner cylinder and the reflux zone serve as the aerobic zone and the anoxic zone in the MBGS process, respectively, to improve the system's treatment efficiency. The aeration system can be connected to treated CO2-containing waste gas. The aeration gas is a mixture of air and CO2, with the proportion of CO2 ranging from 10% to 30%. More preferably, the proportion of CO2 is 15%. The aeration system can also be connected to a micro-nano bubble device to make its aeration bubbles reach the micron level.

3. The low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to claim 1, characterized in that: The stirring device in the primary reaction zone is driven directly by the magnetic field of the base to rotate the fan blades, eliminating the need for an additional motor. The height of the inner straight section is H. The stirring device is equipped with two transparent fan blades, located at 1 / 4H and 3 / 4H below the top of the inner straight section, respectively, to ensure thorough stirring. Transparent fan blades are used to minimize the light-blocking effect of the fan blades.

4. The low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to claim 1, characterized in that: The perforated plate in the primary reaction zone is made of transparent, corrosion-resistant and high-strength material. It is a concave arched plate with a round hole diameter of 3~5 mm, an opening rate of 50%~60%, and an alternating arrangement of equilateral triangles with a slight curvature.

5. The low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to claim 1, characterized in that: The supplemental lighting device uses the middle height of the reactor as the dividing point and adopts a layered multi-band light source structure, which can significantly improve algal biomass and the system's nitrogen and phosphorus removal efficiency.

6. The low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to claim 1, characterized in that: The outer walls of both the primary reaction zone and the supplementary lighting device are made of transparent material. The supplementary lighting device can provide supplementary lighting for both the primary and secondary reaction zones simultaneously.

7. The low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to claim 1, characterized in that: The secondary reaction zone is equipped with a guide pipe with a precisely designed incident angle and flow velocity, which enables the wastewater to form a stable vortex within the secondary reaction zone. This not only enhances mixing and mass transfer but also provides a power source for subsequent hydraulically driven mixing, achieving preliminary energy recovery. Four sets of self-driven stirring devices are set up in the secondary reaction zone, arranged in a vertical cross shape and placed at the center of the inner diameter of the ring; a cone-shaped spiral stirring device with a transparent arc thread is selected. The outlet of the secondary reaction zone is set in a parallel direction to the guide pipe to ensure that the sewage can complete a full swirling process in the secondary reaction zone, thereby extending the hydraulic retention time.

8. The low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to claim 1, characterized in that: The base is an integrated magnetic field-temperature control partitioned base, which integrates a magnetic generation module and a temperature control module. The magnetic generation module of the base is divided into zones according to the reaction characteristics of the primary and secondary reaction zones, and adopts different operating modes according to the reaction stage; the temperature control module of the base operates the temperature control system independently according to the set temperature.

9. The operation method of a low-carbon, high-efficiency wastewater treatment device based on algae-bacterial granular sludge according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Sludge Inoculation and System Start-up Phase Sludge inoculation and activation: Mature algae and bacteria granular sludge with different initial sludge concentrations are added to the inner cylinder of the primary reaction zone and the secondary reaction zone, respectively; Base system activation: Turn on the temperature control module of the base, set and maintain the system temperature; turn on the magnetic generation module and set the zones, start the "constant magnetic field" mode for the primary reaction zone, and temporarily turn off the magnetic field of the secondary reaction zone or use a low intensity background magnetic field. System training: The system adopts a gradual load start-up method, synchronously turns on the supplementary lighting device, and operates according to a layered supplementary lighting strategy; S2, Sunlight Period Operation Mode During the illumination period: In addition to the top of the reactor absorbing sunlight, the concentrator collects sunlight and provides stratified supplemental lighting to the reactor through the supplemental lighting device; The core treatment in the primary reaction zone: wastewater is mixed with high-concentration MBGS in the inner cylinder, where organic matter and nutrients are rapidly absorbed and degraded ("saturation"). The treated mixed liquor rises through the perforated plate, where large-diameter MBGS particles are intercepted. The intercepted granular sludge slides down to the return zone under gravity and rebound, where the anoxic environment prompts microorganisms to utilize endogenous carbon sources for denitrification ("starvation"). Subsequently, the intercepted granular sludge is returned to the bottom of the inner cylinder, completing the "saturation-starvation" cycle. As the supplemental lighting device provides illumination, the algae produce oxygen through photosynthesis, increasing the dissolved oxygen (DO) concentration inside the cylinder; The aeration device is completely shut off or operates at only a very low intensity, significantly reducing energy consumption; the magnetic field of the base drives the transparent fan blades of the mixing device to rotate slowly, allowing MBGS to be fully mixed and in contact with the wastewater, while minimizing light shading. Secondary reaction zone for deep treatment and sedimentation: The supernatant from the primary treatment is temporarily stored in the overflow weir and flows tangentially into the secondary reaction zone through the guide pipe, forming a vortex. The vortex hydraulically drives the self-driven stirring device to rotate, eliminating the need for a motor and achieving energy-saving mixing. In this area, pollutants are further degraded. The centrifugal force generated by the vortex and the magnetic field generated by the base magnetic generation module help to screen sludge particles, with aged fine particles gathering towards the center. The sludge hopper begins to collect the settled aged sludge. The treated clean water flows out through the outlet; S3, Dark Period Operation Mode The reaction zone mode is switched as follows: when light stops, algae stop producing oxygen; the aeration device is automatically activated based on dissolved oxygen (DO) levels, using a "pulse aeration" mode, aerating only when DO is too low, ensuring the oxygen required by nitrifying bacteria while maximizing energy conservation; the magnetic field in the primary reaction zone is switched to an "intermittent magnetic field" mode; in addition, the magnetic field intermittently drives the stirring to run continuously, ensuring the smooth progress of the reaction; periodic magnetic stimulation helps maintain the activity of the microbial community and prevents it from aging and becoming inert. Enhanced sedimentation in the secondary reaction zone: The magnetic field strength in the secondary reaction zone can be appropriately increased to promote the flocculation and sedimentation of MBGS using the magnetic flocculation effect; S4. Routine Maintenance and Sludge Management Water effluent monitoring: Regularly test the water quality at the effluent outlet and fine-tune parameters such as influent flow rate, aeration intensity, and magnetic field mode based on the water quality. Sludge discharge and recycling: Regularly open the sludge discharge valve at the bottom of the sludge hopper to discharge the accumulated aged sludge; the discharged sludge can be further digested, or the still active granular sludge can be recycled, cultivated, and then added back to the reactor to maintain the activity and concentration of sludge in the system.

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